1. Field of the Invention
This invention lies in the field of the combustion of low pressure gases for recovery of their heat value.
More particularly this invention concerns the combustion of very low pressure gases which by their own pressure and velocity, are unable to aspirate sufficient air for combustion.
2. Description of the Prior Art
In the prior art, numerous examples are shown of apparatus for the combustion of gas in a furnace or combustion chamber. These generally have the gas supplied at pressures capable of gas discharge from ports at 100 feet per second or more, and thus at sufficient velocity to aspirate air with the gas to provide for the combustion of the gas. Gases of reference and at pressures of reference seldom flow at greater than 25'/second. Aspiration of air with gas is as velocity squared.
No satisfactory way has been shown for burning of very low pressure gases in furnaces, except for the method taught by this invention.
In oil refineries and petrochemical and chemical plants, there will be, in many cases, waste gases which are fuel rich, but which cannot be used as fuels, because they are available at pressures below that which will permit them to be burned in a satisfactory manner in conventional apparatus.
For various reasons, it is either impossible, or energy wasteful, to compress these gases to make them useful in typical gas burners such as are well known in the art. Gases, as fuels, typically become useful when available at pressures capable, when discharged to atmospheric pressure to produce velocities of flow, which reasonably closely approach critical, or sonic velocity, in order to meet burning requirements for gaseous fuels in the industries mentioned above.
The art will show a number of devices which make use of the discharge of a gaseous fluid, such as steam, or air for inspiration, entrainment of the fuel potential gas, to so accelerate its flow movement as to provide suitable air mixture with the steam-gas, as well as turbulence to permit satisfactory burning. However, in the prior art there is no limitation on the pressures at which the steam or air might be employed. Also the devices for aspiration and entrainment of low pressure gases are comparatively complex.
In this field of art, prior efforts to simplify the structure, or devices required, have exhibited undesirable characteristics, in one respect or another, as fuel burning is considered, although such prior devices have been placed in commercial service despite their many faults. The apparatus of this invention provides a fully satisfactory alternative to the prior art devices.